The present invention refers to a plasma spraying apparatus, particularly for coating the interior walls of tubes and pipes. The plasma spraying apparatus generally comprises a plasma gun shaft member and a plasma gun head member adapted to be fixed to said plasma gun shaft member and having means for creating a plasma torch escaping in radial direction.
Plasma spraying apparatuses having means for creating a plasma torch escaping in radial direction are particularly suited for coating the interior walls of tubes and pipes. In order to enable a relatively small tube or pipe, having an interior diameter of for example 40 mm, to be coated, the plasma spraying apparatus and, particularly, the plasma gun head member, have to be of very compact design. However, if the size of a plasma gun head member is reduced, several problems arise. For example, the thermal load of the plasma gun head member is increased. The result is that certain parts and elements of the plasma gun head, particularly, the cathode thereof as well as the anode, usually designed as a nozzle, are subject to considerable wear. The useful life of these parts and elements is negatively influenced also by the bad heat dissipation during the operation of coating the interior walls of small tubes and pipes.
Thus, it is an object of the present invention to provide a a plasma spraying apparatus, particularly for coating the interior walls of tubes and pipes, having a plasma gun head member that can quickly and easily be replaced. A further object of the invention is to provide a plasma spraying apparatus, particularly for coating the interior walls of tubes and pipes, in which the parts and elements of the apparatus that are subject to wear can easily and quickly be replaced.
To meet these and other objects, the invention provides, in a first aspect, a plasma spraying apparatus, particularly for coating the interior walls of tubes and pipes, comprising a plasma gun shaft member having a central longitudinal axis, and a plasma gun head member having a central longitudinal axis, adapted to be fixed to the plasma gun shaft member and having means for creating a plasma torch escaping in radial direction.
The plasma gun head member comprises an anode base body member, a cathode base body member and an insulating body member located between the anode base body member and the cathode base body member. The anode base body member is provided with at least one electrical contact element adapted to transmit operating power from the plasma gun shaft member to the plasma gun head member, and the cathode base body member is also provided with at least one electrical contact element adapted to transmit operating power from the plasma gun shaft member to the plasma gun head member.
The plasma gun shaft member is provided with quick release clamping means for connecting the plasma gun head member to the plasma gun shaft member, whereby the insulating body member towers above the face of the plasma gun head member that is intended to be connected to the plasma gun shaft member. Moreover, the insulating body member is provided with surface means adapted to be engaged by the quick release clamping means provided on the plasma gun shaft member.
According to a second aspect, the invention provides a plasma spraying apparatus, particularly for coating the interior walls of tubes and pipes, comprising a plasma gun shaft member having a central longitudinal axis, and a plasma gun head member having a central longitudinal axis, adapted to be fixed to the plasma gun shaft member and having means for creating a plasma torch escaping in radial direction.
The plasma gun head member comprises an anode base body member, a cathode base body member and an insulating body member located between the anode base body member and the cathode base body member. The anode base body member is provided with at least one electrical contact element adapted to transmit operating power from the plasma gun shaft member to the plasma gun head member, and the cathode base body member is also provided with at least one electrical contact element adapted to transmit operating power from the plasma gun shaft member to the plasma gun head member.
The plasma gun shaft member is provided with quick release clamping means for connecting the plasma gun head member to the plasma gun shaft member, whereby the electrical contact element provided on the anode base body member and the electrical contact element provided on the cathode base body member tower above the face of the plasma gun head member that is intended to be connected to the plasma gun shaft member and is provided with surface means adapted to be engaged by said quick release clamping means provided on the plasma gun shaft member.
According to a third aspect, the invention provides a plasma spraying apparatus, particularly for coating the interior walls of tubes and pipes, comprising a plasma gun shaft member having a central longitudinal axis, and a plasma gun head member having a central longitudinal axis, adapted to be fixed to the plasma gun shaft member and having means for creating a plasma torch escaping in radial direction.
The plasma gun head member comprises an anode base body member, a cathode base body member and an insulating body member located between the anode base body member and the cathode base body member. The anode base body member is provided with at least one electrical contact element adapted to transmit operating power from the plasma gun shaft member to the plasma gun head member, and the cathode base body member is also provided with at least one electrical contact element adapted to transmit operating power from the plasma gun shaft member to the plasma gun head member.
The plasma gun shaft member is provided with quick release clamping means for connecting the plasma gun head member to the plasma gun shaft member, whereby the insulating body member as well as the electrical contact element provided on anode base body member and the electrical contact element provided on the cathode base body member tower above the face of the plasma gun head member that is intended to be connected to the plasma gun shaft member and is provided with surface means adapted to be engaged by the quick release clamping means provided on the plasma gun shaft member.